Two dead as storms rip through NSW

FLOODING in NSW has claimed two lives, cut roads and power and prompted evacuation orders for communities along the mid-north coast.

A 17-year-old boy died after being swept into a drainpipe on Friday night as he was collecting golf balls in waist-deep water in the town of Kew.

Early on Saturday afternoon the body of a man was found in his submerged car on a flooded road at Mylneford, about 20km northwest of Grafton.

NSW Police have urged motorists to avoid driving into floodwaters following the man's death and more than 20 rescues from floodwaters as a low pressure system tracked south bringing heavy rain and winds.

Evacuation orders were issued on Saturday for communities along the mid-north coast as rising rivers were predicted to overtop levees and cause flooding.

Kempsey's central business district was expected to be flooded late on Saturday night.

The flooding has forced roads closures, including parts of the Pacific Highway and other major routes, and the wild weather has cut power to thousands of residents.

Around 100 train passengers on the Countrylink XPT service from Sydney to Casino were trapped for nearly 17 hours after fallen trees, floodwaters and a landslide stopped the train three times before it reached Coffs Harbour at midday on Saturday.

Meanwhile, a Westpac Lifesaver rescue helicopter on Saturday afternoon flew a family of eight, including a newborn baby, to Port Macquarie from a farm cut off by floodwaters about 30km west of Wauchope.

The chopper was also diverted to rescue a woman trapped in her car by floodwaters.

On Saturday afternoon an evacuation order was issued for downtown residents and businesses of Kempsey as the Macleay River rose and was expected to flood the central business district on Saturday night.

Another evacuation order was issued for low-lying parts of Port Macquarie and surrounds while other communities, including around Grafton and Bellingen, as well as parts of Lismore in the state's north, were issued with warnings.

The Bureau of Meteorology predicted the Macleay River at Kempsey Bridge would peak near 7.3 metres at 6am (AEDT) on Sunday with further rises possible.

NSW's Transport Management Centre urged motorists not to travel on the mid-north or north coast because of closures in place on the Pacific and Oxley Highways and other major roads.

It said the New England Highway remained an alternative route to and from Queensland.

The State Emergency Service said that by mid-Saturday afternoon it had attended 2162 call-outs in storm-affected communities.

It said nearly 18,400 people and 7350 dwellings were subject to evacuation orders in northeast NSW and around 3700 people were isolated by floodwaters.

Up to 20,000 residents were affected by power cuts caused by storms.

The Bureau of Meteorology said the low would track slowly towards the southwest to be near Dubbo late on Saturday evening, with widespread rain expected in eastern NSW.

Gales were expected in coastal areas with damaging gusts and surf but conditions are expected to ease on Sunday.